1. Field of the Invention
The present invention relates to a growth method of an inorganic compound single crystal and a boat used for the growth method of a single crystal. More particularly, the present invention relates to a method for producing, at a high yield, a single crystalline inorganic compound of a IIIb group element(s) and a Vb group element(s) of the Periodic Table by means of a boat growth method. The inorganic compound(s) of a IIIb group element(s) and a Vb group element(s) is hereinafter referred to as an inorganic compound(s).
2. Description of the Prior Art
Single crystalline inorganic compounds, such as GaAs or the like, are produced in most cases by means of the boat growth method. The inorganic compound is melted and then solidified by the gradient freeze (GF) method or the horizontal Bridgeman (HB) method, using a boat. The boat has a semicircular or oval cross section and is made of quartz.
It is known to roughen the inner surface of the boat by means of sand-blasting or the like so as to prevent the inner surface from being wetted by the melt of the inorganic compound. The sand blasting is carried out with finely divided alumina, SiC, or similar powder. If wetting occurs, the silicon of the boat is incorporated into the single crystalline inorganic compound and twins and grain boundaries are generated during growth, thereby lessening the yield of the single crystalline inorganic compound.
The known roughening method is, however, not very effective for preventing wetting in the case of producing a single crystal having a large cross section since the amount of charged melt is great and tends to wet the inner surface of the boat. The known boat growth method involves a difficulty in producing a single crystalline inorganic compound at a high yield.